Bruxism is the grinding of the teeth, typically accompanied
by the clenching of the jaw. It is an oral parafunctional
activity that occurs in most humans. Bruxism is caused by
the activation of reflex chewing activity; it is not a learned
habit. Chewing is a complex neuromuscular activity that is
controlled by reflex nerve pathways, with higher control by
the brain. During sleep, the reflex part is active while the
higher control is inactive, resulting in bruxism. In most
people, bruxism is mild enough not to be a health problem;
however, some people suffer from significant bruxism that
can become symptomatic.
The aetiology of bruxism is
unknown, but may include asymmetrical occlusion, anxiety,
digestive problems, a disturbed sleep pattern, or hypersensitivity
of the dopamine receptors in the brain.
Bruxism can cause indentations
in the teeth, wear of the biting surface, abfractions and
cracks in the teeth. This type of damage is categorised as
symptomatic of an occlusal disease.
occurs during sleep and can even occur during short naps.
In a typical case, the canines and incisors are moved against
each other laterally, i.e. with a side-to-side action by the
lateral pterygoid muscles that lie above and to the sides
behind the mouth. This lateral movement abrades tooth enamel,
removing the sharp biting surfaces and flattening the edges
of the teeth.
bruxism sometimes also grind the molars together, which can
be loud enough to wake a sleeping partner. Some will clench
without significant side-to-side jaw movement. Bruxism is
one of the most common sleep disorders: Given enough time,
dental damage will usually occur. Bruxism is the leading cause
of occlusal disease and a significant cause of tooth loss.
bruxing shortens and blunts the teeth being ground, and may
lead to myofacial muscle pain and headaches. In severe, chronic
cases, it can lead to arthritis of the temporomandibular joints
(the joints of the jaw). Most people are not aware of their
bruxism and only 5 to 10 percent go on to develop symptoms
such as jaw pain and headache. Teeth hollowed by previous
decay (caries) may collapse as the pressure exerted by bruxism
on the teeth is extraordinarily high.
introduced device called the BiteStrip enables at-home overnight
testing for sleep bruxism and might help diagnose bruxism
before damage appears on the teeth. The device is a miniature
electromyograph machine that senses jaw muscle activity while
the patient sleeps. A dentist can establish the frequency
of bruxing, which helps in choosing a treatment plan. Anyone
having major occlusal rehabilitation should be aware that
bruxism can and does ruin dental work.
of the condition may be quite advanced before sufferers are
aware they brux. Abraded teeth are usually brought to the
patient's attention during a routine dental examination. If
enough enamel is abraded, the softer dentine will be exposed
and abrasion will accelerate. This opens the possibility of
dental decay and tooth fracture--and in some people, gum recession.
Early intervention by a dentist is advisable.
not the only cause of tooth wear. Overly vigorous brushing,
abrasives in toothpaste, acidic soft drinks and abrasive foods
can also be contributing factors; each has characteristic
wear patterns that a trained professional can identify.
caused by drug use
are known to cause bruxism as a side effect, e.g. MDMA and
others of the amphetamine-based family. Drug users who experience
bruxism often refer to the grinding of teeth as "gurning."
use (i.e. frequent redosing and dependancy) of GHB and similar
GABA inducing analogues such as Phenibut are also known to
There is no
accepted cure for bruxism. Ongoing management of bruxism is
based on minimizing the abrasion of tooth surfaces by the
wearing of an acrylic dental guard, designed to the shape
of an individual's upper or lower teeth from a bite mould.
Mouthguards are traditionally obtained through visits to a
dentist for measuring, fitting, and ongoing supervision.
mouthguards are also available by mail, using home dental
moulds, and non-custom mouthguards are available at drug stores
in some countries. However, professional treatment is medically
recommended to ensure proper fit, make ongoing adjustments
as needed, and check that the occlusion (bite) has remained
stable. Monitoring of the mouthguard is suggested at each
dental visit. Serious and irreversible complications can result
from long term use of mouthguards.
The main goal of treatment is to prevent further tooth damage,
and requires that the night guard be worn as long as the person
There is limited
evidence that suggests taking certain combinations of vitamin
supplements may alleviate bruxism.
One way of stopping the damage and severity of grinding and
clenching is through the making of a repositioning splint.
A repositioning splint looks like the traditional night guard,
but has certain functions built into it. This device supposedly
not only protects the teeth when grinding, but also reduces
the urge to grind. The efficacy of such devices is unproven.
devices are available that, as of 2007, are as yet unproven
in effectiveness. While there is anecdotal evidence that they
are of some use, there are detractors among bruxism professionals.
One of these devices is the Oralsensor, which comprises a
pneumatic pouch embedded in a soft polymer plate that fits
over upper or lower teeth. When the teeth come together—to
a threshold pressure set each night by the user—an alarm is
sounded in an earpiece worn by the user.
device, GrindAlert, is a battery-powered device that sounds
a tone when it senses EMG (electromyographic) muscle activity
in the temporalis muscles of the forehead. In 2005, a new
type of occlusive device was patented that produces a movement
incompatible with teeth clenching. When nighttime bruxism
occurs, people breathe through the nose. The new device forces
people to breathe through the mouth; thus, by forcing the
opening of the mouth, the device is claimed to stop clenching.
device has an electromyogram system that monitors the electric
activity of the jaw muscle via wireless electrodes. These
electrodes transfer jaw-muscle activity by radio frequency
to an external monitoring system. Once the signal has been
interpreted by the monitoring system, if a patient clenches
(i.e., if the signal transmitted by the electrodes is higher
than a given threshold), the monitoring unit sends a radio
frequency signal to a transceiver integrated in a mechanical
actuator has two occlusive flaps that block the nostrils,
forcing breathing to occur through the mouth. Once the patient
stops clenching (i.e., once the signal is under the threshold),
the flaps open, allowing breathing through the nose again.
The occlusive device does not wake up people since it blocks
nostrils slowly, and it never closes them completely to avoid
damage to teeth from bruxism
can be repaired by replacing the worn natural crown of the
tooth with an artificial crown. Materials used to make crowns
vary; some are less prone to breaking than others, and can
last longer. Porcelain fused to metal crowns may be used in
the anterior (front) of the mouth; in the posterior (back)
gold is the preferred material. All porcelain crowns are now
becoming more and more common and work well for both anterior
and posterior restorations. To protect the new crowns and
dental implants, an occlusal guard may be fabricated to wear
may find that meditation and relaxation techniques, like any
other tactic to reduce stress, may help to reduce teeth grinding.